Reset Keyboard Preferences
When I first installed Ubuntu it worked flawlessly and the sound control buttons on my keyboard worked as expected. But now I just configured volume up, volume down, and mute to other key combos but when I set them back to their default keys they don’t work anymore.
So I was guessing if there was a way to reset the functions each key to stock Ubuntu state?
Solution 1:
Open a Terminal (Ctrl+Alt+t) and type:
dconf reset -f /org/gnome/settings-daemon/plugins/media-keys/
It will restore the default settings for all your media keys.